package threads;

import java.util.Random;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

public class ReadWriteLockTest {
    static Lock lock = new ReentrantLock();
    private static int value;
    static ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
    static Lock readLock  = readWriteLock.readLock();
    static Lock writeLock  = readWriteLock.writeLock();

    public static void read(Lock lock) {
        try {
            lock.lock();
            Thread.sleep(1000);
            System.out.println("read over!");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }

    }
    public static void write(Lock lock,int v) {
        try {
            lock.lock();
            Thread.sleep(1000);
            value = v;
            System.out.println("write over!");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public static void main(String[] args) {
        Runnable readR = new Runnable() {
            @Override
            public void run() {
                read(readLock);
            }
        };
        Runnable writeR = new Runnable() {
            @Override
            public void run() {
                write(writeLock,new Random().nextInt());
            }
        };
        for (int i = 0; i < 18; i++) {
            new Thread(readR).start();
        }
        for (int i = 0; i < 2; i++) {
            new Thread(writeR).start();
        }
    }
}
